Integrated circuit memory cells typically have a limited useful lifespan, e.g., due to degradation of cell performance over time. For example, certain flash memory cells may wear out after repeated program/erase cycling, e.g., in the range of 100,000 to 10 million cycles. In a typical flash memory cell, the erase performance degrades faster than the program performance, as a function of program/erase cycles.
FIG. 1 shows the effects of program/erase cycling on an example flash memory cell having a pair of floating gates. In particular, FIG. 1 shows example measured erase current data (Ir1) as a function of program/erase cycles and measured program current data (Ir0) as a function of program/erase cycles. As shown, the erase current (Ir1) degrades faster than the program current (Ir0), as a function of program/erase cycles. Thus, the effective lifespan of such memory cell may be limited by the erase cycling of the cell.